Pneumatic tire

Abstract

This invention relates to pneumatic tires and more particularly to a so-called safety tire comprising a carcass having a tube accommodated therein and spaced from the carcass to form inner and outer air chambers. A loose, circumferentially extending, puncture-resistant band is positioned substantially in the mid-circumferential plane of the tire between the underside of the tire tread and the tube. A further feature of the invention is the provision of means which produces an audible signal should the outer chamber become deflated. Another feature of the invention is the provision of means which, in use, limit radial and/or axial expansion of the tube should the outer chamber become deflated. A final feature is the provision of means which inhibit or prevent removal of the bead portions of the tire. from their respective seats upon deflation of the tire.

I claim: 
     
       1. A pneumatic tyre comprising a carcass, a tube accommodated in the carcass and spaced therefrom to form inner and outer air chambers, a loose, circumferentially extending, puncture-resistant band positioned substantially in the mid-circumferential plane of the tyre between the underside of the tyre tread and the tube, said band including irregular passages extending therethrough, and wherein said passages are provided with means which are operative for producing an audible signal when air passes therethrough. 
     
     
       2. A pneumatic tyre as claimed in claim 1, wherein there is provided projections on the inner surface of the carcass for restricting lateral movement of the band. 
     
     
       3. A pneumatic tyre as claimed in claim 1, wherein the band is constructed of a material having multiple air pockets therein. 
     
     
       4. A pneumatic tyre as claimed in claim 1, including spacer means provided on the inside of the carcass at the underside of the tyre tread. 
     
     
       5. A pneumatic tyre as claimed in claim 1, including spacer means provided on at least one circumferential surface of the band. 
     
     
       6. A pneumatic tyre as claimed in claim 1, including spacer means provided on the surface of the tube confronting the outer air chamber. 
     
     
       7. A pneumatic tyre as claimed in claim 5, wherein said spacer means comprise acoustical air chambers. 
     
     
       8. A pneumatic tyre as claimed in claim 1, wherein the band comprises at least one reinforcing layer. 
     
     
       9. A pneumatic tyre as claimed in claim 8, wherein each reinforcing layerconsists of separate layers of material. 
     
     
       10. A pneumatic tyre as claimed in claim 1, wherein the band is provided with a series of intermeshing reinforcing layers. 
     
     
       11. A pneumatic tyre comprising a carcass, a tube accommodated in the carcass and spaced therefrom to form inner and outer air chambers, and a compressible material provided with a plurality of air pockets having discharge apertures, said material being positioned on the underside of the tyre tread and exteriorly of the tube, the arrangement being such that when the outer air chamber deflates the compression of the material between the tube and the underside of the tyre tread adjacent the area of contact of the tyre with the road produces continuous ingress and egress of air from the pockets to thus produce an audible signal indicative of the deflated condition of the outer air chamber, and wherein said air pockets are provided with insert means for assisting in the production of said audible signal. 
     
     
       12. A pneumatic tyre as claimed in claim 11, including means in said tube for restraining outward circumferential movement of the tube. 
     
     
       13. A pneumatic tyre as claimed in claim 12 wherein said restraining means comprise elastic web members integrally formed within said tube and extending across a diameter of the tube cross-section.